55613509 has 4 divisors (see below), whose sum is σ = 63558304. Its totient is φ = 47668716.

The previous prime is 55613489. The next prime is 55613521. The reversal of 55613509 is 90531655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55613509 - 2⁷ = 55613381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55613539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3972387 + ... + 3972400.

It is an arithmetic number, because the mean of its divisors is an integer number (15889576).

Almost surely, 2^55613509 is an apocalyptic number.

It is an amenable number.

55613509 is a deficient number, since it is larger than the sum of its proper divisors (7944795).

55613509 is an equidigital number, since it uses as much as digits as its factorization.

55613509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7944794.

The product of its (nonzero) digits is 20250, while the sum is 34.

The square root of 55613509 is about 7457.4465469087. The cubic root of 55613509 is about 381.7040483420.

The spelling of 55613509 in words is "fifty-five million, six hundred thirteen thousand, five hundred nine".